Method of coating sheet material



C. O. KILHAM METHOD OF COATING SHEET. MH'I'ERiAL Jan. 16, 1934.

Original Filed May 10. 1930 Patented Jan. 16, 1934 UNITED STATES PATENTFFICE METHOD OF COATING SHEET MATERIAL Original application May 10,1930, Serial No.

451,451. Divided and this application February 6, 1933.

6 Claims.

This invention concerns the coating of sheet material, and is hereinexemplified with special reference to the coating of sheet materialwhich has its margins beveled or otherwise made thinner than the body ofthe sheet.

Machines of the character described in Letters Patent of the UnitedStates No. 1,656,346, granted January 1'7, 1928, upon an application ofJohn W. Cosgrove, are designed to operate upon material in the form ofsheets, of which the opposite faces are substantially parallelthroughout. In the manufacture of shoes, for example, work is sometimesencountered which, instead of having such parallel faces, is thinner atthe margins. Thus, rubber soles for shoes commonly have peripheralbevels at the tread side. When such soles are freshly cut, the facewhich is to be cemented to the insole may be plane; but, as they age,the margin tends to curl toward the beveled side, making it difiicult toapply cement properly to this thin, distorted margin. An object of thepresent invention is to provide for coating, in a substantially uniformmanner and expeditiously, entire faces of sheets having such reducedmargins.

For the attainment of this object, my invention contemplates a method ofcoating which may consist in applying a coating progressively to oneface of a sheet of material while the sheet is bent about alinesubstantially parallel to the direction of progress, thereby stretchingthe outer face, the coating being applied to the face which is undergreater tension. Such stretching draws the margin toward the coatinginstrumentality, rendering the surface fully accessible. Considering theinvention in another aspect, the sheet will be made convex upon the faceto be coated, as by stretching and, bending it, for example by pressingit against a concave surface which has been supplied with a coatingsubstance.

In performing the method above set forth, I may utilize an apparatus ofthe type disclosed and claimed in an application Serial No. 451,451,filed May 10, 1930, in my name, and of which this application is adivision. In that apparatus, an applying roll, with its applying surfacecurved longitudinally of the axis of rotation, operates in a receptaclefor a coating substance and has cooperating with it a rotatable pressureroll with its surface oppositely curved. The applying roll is preferablyconcave and the pressure roll convex. Thus, when the work is pressedagainst the concave applying roll by the convex pressure roll, there isobtained the desired stretching of the surface to be coated and thesimultaneous Serial No. 655,368

application of the coating substance. Such an apparatus, useful but notessential in carrying out my improved method, is illustrated in theaccompanying drawing, in which Fig. 1 shows such a machine in brokenside 0 elevation;

Fig. 2 is a transverse section on the line II-II of Fig. 1;

Fig. 3 is a fragmentary view showing, on an enlarged scale, a portion ofthe sole and the rolls, as in Fig. 2; and

Fig. 4 is an enlarged cross-section through a rubber sole the edges ofwhich have curled from their original shape, which latter is shown indotted lines.

For the general construction of the present apparatus and for certaindetails which have no particular bearing upon my invention, referencemay be had to the previously mentioned patent. A tank or receptacle 10,adapted to contain the cement or other coating substance to be applied,has journaled in its side walls a horizontal shaft 12 for a rotatableapplying roll 14, the lower portion of which lies in the containedadhesive. The applying surface of this roll is preferably 30 concave,being gradually curved longitudinally of its periphery from ends ofmaximum diameter to a reduced central portion. The roll is rotated, inthe direction indicated by the arrow in Fig. 1 of the drawing, byconnections at 16 through a counter-shaft 17 to a motor, and is suppliedwith work-pieces over a table or conveyor 18, the coated pieces beingremoved by a conveyor 20 at the opposite side of the roll 14.

To hold the work in contact with the roll 14 during the progressivecoating operation, and to aid in its advance, an upper pressure roll 22is rotatable about the axis of a shaft 24 parallel to and verticallyalined with the shaft 12. The shaft 24 is journaled in side arms of aframe 26 pivoted at 28, 28 upon a bridge 30 rising from the sides of andextending across the top of the tank. The roll 22 is convex, itslongitudinal curvature being substantially concentric to the surface ofthe roll 12. As illustrated, it is in three independent sections. Thatat the center, to which the numeral 22 has been applied, is fast uponthe shaft 24. The adjacent sections 32, 32, at its opposite sides, areloose upon the shaft. The ends of the sections operate substantially incontact with one another, the convex surface of the roll 22 being thuspractically unbroken. Extending upwardly from the frame 26, at oppositesides of the bridge, are two projections 34 and 36, the 110 formerhaving interposed between it and the bridge a spring 37, which exertsits force constantly to urge the roll 22 toward the applying roll 14.Threaded through the other projection is a screw 38, bearing at itsinner extremity against the bridge. By differently positioning thisscrew, the normal separation between the rolls may be varied, thusadapting the apparatus to operate to the best advantage upon sheets ofdifferent thicknesses. The roll 22 is rotated oppositely to the roll 14,the central section having the same peripheral speed as suchapplying-roll. This is accomplished by gearing 40 joining the shaft 24to a counter-shaft 42 horizontally alined with the pivotal points 28 ofthe frame 26, and gearing 44 between said counter-shaft and the shaft17.

In utilizing this apparatus to carry out my improved method, andassuming that rubber soles S beveled to form an inclined edge 46 abouttheir tread faces T are to be cemented upon the larger face 48 oppositeto the tread face, the operator feeds the work-pieces successivelybetween the oppositely rotating applying roll 14 and the pressure roll22 from the table 18, the face opposite the tread being down. As eachsole is advanced through the rolls by their rotation, the upper rollpresses it into the concavity of the applying roll, bowing it downwardlyand outwardly about a line substantially parallel to the direction ofprogress and stretching the lower larger face 48 transversely as thecoating is applied. This strain upon the material draws down the thinmargin formed by the convergence of the beveled edge with the largerface of the sole at 50, so that, even if it is curled over' toward thetread face T, as indicated in Fig. 4, or is in an uneven wave form, thetension holds it firmly against the applying surface, which will layupon the lower face 48 a substantially uniform coating extending to thevery edge. If a sole enters the rolls at one side of their longitudinalcenters, no appreciable retarding effect is produced by those moreslowly rotating peripheral portions of the pressure roll which are ofless diameter than the central portion, since the two outer sections 32,32 are not driven and can turn with the sole as it travels beneath them.The departure of the central driven portion of the roll-22 from thecylindrical form is not suflicient to impart to the work-pieces anangular deflection, so their travel is along a substantiallystraightline. This freedom of the end sections of the pressure roll inno way impairs its ability to maintain a proper contact of the surfacebeing cemented with the applying roll. The sole operated upon thusemerges from between the rolls, upon the conveyor 20, with its entirelower face cemented.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

1. The method of coating a piece of sheet material having opposite thinmarginal portions which consists in applying a coating progressively toone face of the material and simultaneously bending the sheet about aline substantially parallel to the direction of progress thereby tostretch one face more than the opposite face, the coating being appliedto that surface which is under greater tension.

2. The method of coating unattached soles having beveled edges, whichconsists in supplying a concave surface with a coating substance,pressing a sole against the concavity with the inclined edge away fromthe coated surface, and moving the sole over said surface.

3. The method of coating a sole having beveled edges and with one facewhich is larger than the other and terminates in a thin margin, whichconsists in bending said sole transversely to stretch the larger face,and simultaneously applying a coating to the whole width of the largerface.

4. The method of coating a sole having its edge beveled to provide oneface larger than the other with the inclined edge forming a thin marginaround the larger face, which consists in supplying a concave surfacewith a coating substance, and exerting pressure against the smaller faceof such a sole to force the larger face including its thin marginagainst said coated concave surface.

5. The method of coating a sole having one face larger than the otherand which faces are joined by a sloping edge surface, which consists insupplying a concave surface with a coating substance, pressing thelarger face against the concave surface, thereby to stretch the largerface to bring all portions thereof firmly into contact with said concavesurface, and moving the sole over said coated concave surface whilemaintaining said stretched condition.

6. The method of coating soles having beveled edges which consists inbending said soles transversely between oppositely curved surfaces,thereby to stretch one face of each sole to cause said face includingthe margin thereof to contact firmly with one of the surfaces, supplyinga coating substance to said latter surface, and causing relativemovement between said surfaces and the sole to coat one face of the solewhile maintaining the bent relation thereof.

CHARLES O. KILHAM.

